Excellence in Energy Efficiency

In 2008, Chattanooga-based architectural firm Hefferlin + Kronenberg (HK) began planning the renovation of the south tower and community center of Mary Walker Towers (MWT) a low-income housing community for senior citizens ages 50 or older, owned and operated by the Chattanooga Housing Authority (CHA).

The facility is located in the Southside of Chattanooga across the Street from Howard High School. The complex is named after Mary Walker who was born a slave in Alabama in 1846 and moved to Chattanooga in 1917. At age 116 she enrolled in one of the earliest Chattanooga Literacy Movement classes and studies English and arithmetic. She was declared the oldest student in the nation by the U.S Department of Health, Education and Welfare and is generally considered to be an inspirational figure in local African-American history.

Originally built in 1971, the complex bearing Walker’s name includes two towers connected by a one-story community building. There are 53 one-bedroom apartments in the north tower and 100 one-bedroom units in the south tower. The north tower underwent modernization in 2001 and that included the addition of efficent lighting, water saving devices, heat pumps, new cabniets, flooring, and painting.

Sunshades help reduce heat

HK Architects was retained to prepare plans for the modernization of the south tower and the community center. The focus of the renovation was to repair infrastructure, improve energy efficiency, and to bring the building up to current codes. Naveed Minhas, vice president of development, oversaw the project for CHA.

“Maintaining our properties while improving every efficiency is the goal of all our modernization projects. This was a perfect fit for HUD’s Recovery and Reinvestment Act which provided the funding for the project,” says Minhas. “Along with the energy and code work, we challenged HK to get the input of the residents on the selection of the colors and interior finishes.”

Heidi Hefferlin, managing partner at HK, explains, “To start the project we held a series of meetings with the building residents to talk with them about any problems they saw with the project, or what they would like to have done.”

green|space Chattanooga funded the Live Roof Module System.

Residents expressed the need for better lighting in the corridors, improved laundry facilities and improvements of the garden area. “We also took a survey of the colors the residents would prefer,” says Hefferlin. “One of the items that came out of the meetings was to give each floor an identity. We did this by changing the corridor colors on each floor. Other improvements addressed code requirements, such as remodeling five of the units to become wheelchair accessible and adding fire sprinklers to the building. The highest priority, however, was improving the energy efficiency in the buildings.

“The housing authority came to us because they needed to modernize the building and to improve the energy efficiency. We also changed all the finishes in the interior: a new vinyl composition tile flooring, new paint, and changed all the kitchen cabinets.”

Hefferlin says all the windows in the building were replaced. Previously, they were single-glazed windows and have now been replaced by dual-glazed ones.

“We added sun shades on the east and south facades to reduce solar heat gain. We insulated the walls around the windows that were not brick and added new insulation and a green roof on the community center,” she says.

Bath

The green roof was installed in June 2011 using the LiveRoof module system. This part of the project was funded by Green|Spaces Chattanooga, and the system was planted by Chattanooga-based Sterchi Construction. According to a press release on the CHA website, “the 2,200-sqaure-foot green roof features nearly 100 trays of full-grown vegetated sedum that will sit atop a water-resistant membrane covering that spans the entire roof. The sedum blooms in the spring and summer, and will remain green in the cooler months.” A timed irrigation system will provide water during the hottest and driest months. Sterchi construction workers regularly check to make sure the irrigation system is functioning properly. They also fertilize, weed and monitor the health of the plants.

The green roof provides multiple benefits to the project including decreased storm water runoff, reduction of the heat island effect, added insulation and protection of the roof membrane, and the beauty its vegetation brings to the residents who now look down on plants rather than a black rooftop.

One of the biggest challenges was working within a projected that could not be vacated. Clif McCormick, project manager for HK, and P&C Construction worked closely with Lonnie Edwards of the housing authority to develop a rotating plan that provided for four floors to be renovated at a time. “A temporary construction elevator was set up on the exterior of the building for moving construction materials, leaving the building elevator in service for the residents,” says McCormick. As construction progressed, residents moved and returned.

Kitchen

CHA Executive Director Betsy McCright says the agency has enjoyed its partnership with the architectural firm. “We’ve worked with HK on other development projects and have always been pleased with the finished product. Mary Walker Towers is no exception. We’re proud of what’s been accomplished at this site, and so are the residents.”

With the completion of the project the residents are enjoying better lighting, more cheerful colors, new appliances, and improved temperature regualtion. A view of the roof garden and new finshes in the apartments make for better living. Because the LiveRoof system is so new, statistics are currently unavailable with regard to how much energy has been saved, but feedback has been positive. “The resdients are more comfortable,” says McCormick. “So we know that it’s making a big difference.”
H+K website: www.hkarchitects.net
Housing Authority website: www.chahousing.org

Story by Katie Freeland
Photography by Harlan Hambright

This story was originally published in the Dec/Jan 2012 Issue of Chattanooga Magazine.